gistfile1.txt

class RPNCalculator
  @rpn
  
  def initialize
    @rpn = []
  end
  
  def push(num)
    @rpn << num
  end
  
  def plus
    value1 = @rpn.pop
    value2 = @rpn.pop
    self.push(value2 + value1)
  end
  
  def minus
    value1 = @rpn.pop
    value2 = @rpn.pop
    self.push(value2 - value1)
  end
  
  def times
    value1 = @rpn.pop
    value2 = @rpn.pop
    self.push(value2 * value1)
  end
  
  def divide
    value1 = @rpn.pop
    value2 = @rpn.pop
    self.push(value2.to_f / value1.to_f)
  end
  
  def value
    @rpn.last
  end
end